Conventionally, home video recorders which use a magnetic tape such as a VHS tape as a recording medium are popularly used. Along with recent penetration of personal computers, recording devices such as a hard disk drive (to be referred to as an HDD hereinafter) are increasing the capacities, and their prices are also becoming low. Digitization of such video devices is also progressing. Especially, for video cameras, the DV scheme is becoming the mainstream.
Under these circumstances, digitization of home video recorders has also started. Some products are available now, which use, as a recording medium, an optical disk such as a writable DVD medium or an HDD, and encode image and audio data by MPEG2 and record/playback them. These products have a recording/playback function taking advantage of the random accessibility of the recording medium, unlike the conventional products which use a video cassette with a magnetic tape as a recording medium. More specifically, a number of useful functions are implemented, including content management or playback using the random accessibility, long-time recording by compression-coding, and recording/playback concurrent execution in which an already recorded content is played back while executing recording.
In addition, a number of models of hybrid recorders are also commercially available and are becoming popular. The hybrid recorders have a permanent bulk HDD and an optical disk drive which uses a detachable optical disk as a recording medium. In such a product, the user can select an optical disk or HDD for recording. Furthermore, a recorded file can be copied or moved from one to the other.
Some models have a function of automatically recording a program in the HDD from the beginning when, although an optical disk is selected as a recording medium for scheduled recording, no optical disk is loaded or the remaining capacity of a loaded optical disk is insufficient for recording the preselected program, or a function of automatically causing the HDD to continuously execute recording when the remaining capacity of the optical disk has decreased to a predetermined level or less during recording (Japanese Patent Laid-Open No. 2002-74839 (reference 1)). In the latter function, one program (content) is recorded while extending over the optical disk and HDD.
In the prior art of reference 1, assume that one content is recorded over an optical disk and HDD, and, of the content recorded over the two recording media (such a content will be referred to as a relay content hereinafter), only the data recorded on the optical disk is played back by another device. In this case, the user cannot know whether the content recorded on the optical disk comes to a full stop or has more to follow. That is, the user cannot recognize that the data played back is a relay content.
Similarly, assume that the optical disk on which the first half of the relay content is recorded is not loaded in the recorder, and only the data of the second half of the relay content recorded in the HDD is played back. In this case, the user cannot recognize whether the data of the first half of the content is recorded separately. Even when the content is a relay content, there is no means for notifying the user of it.
In reference 1, if the user wants to record the relay content wholly on one disk, the part recorded on the optical disk must temporarily be saved in the HDD. Then, the user newly inserts a blank disk.
Assume that image data played back from, e.g., a video tape is recorded on an optical disk, and a part unrecorded due to shortage of the storage capacity of the optical disk is continuously recorded in the HDD (relay recording). At this time, recording in the HDD cannot be executed from a proper point to start.